Solar light active flexible activated carbon cloth‐based photocatalyst for Markovnikov‐selective radical‐radical cross‐coupling of S‐nucleophiles to terminal alkyne and liquefied petroleum gas sensing

Selective radical‐radical coupling of terminal alkynes and thiol has been broadly used in chemical synthesis, providing plausible entries to the formation of anti‐Markovnikov products. Because of the selective control and Kharasch effect, the formation of Markovnikov products still remains an immense challenge. Herein, we designed a covalent organic polymer, poly(naphthalene 1,4,5,8‐tetracarboxylic dianhydrideimide‐benzoquinone) through in situ polymerization on activated flexible carbon cloth to function as a light harvester material for selective Markovnikov radical‐radical coupling of terminal alkynes and thiol. Mechanistic explorations verified that cross‐coupling between radical of terminal alkynes and thiol might be the key route in this organic transformation, such as C—S bond formation. This selective radical‐radical Markovnikov of cross‐coupling protocol provide an opportunity to assist the synthesis of valuable vinyl sulfide. Additionally, the synthesized material has been explored as liquefied petroleum gas (LPG) sensor for 0.5, 1.0, 1.5, and 2.0 vol% LPG, respectively. At 2.0 vol% LPG, it shows maximum sensor response as 635.29. Least response and recovery times are 2.44 and 1.0 s, respectively. A newly designed highly efficient solar light active covalent organic polymer, poly(naphthalene 1,4,5,8‐tetracarboxylic dianhydrideimide‐benzoquinone) through in situ polymerization on activated flexible carbon cloth (PNIB‐AFCC) photocatalyst is used for selective radical‐radical cross coupling of terminal alkynes and thiol. This selective radical‐radical Markovnikov of cross‐coupling reaction has been providing an opportunity to aid the solar chemical synthesis. Additionally, this PNIB‐AFCC photocatalyst is proven as an excellent liquefied petroleum gas sensor with better response and recovery time.